Franz I've been involved in the infinite scrolling behavioural research tests from etsy back then. As your post already states, pagination is a mental model that is well established, though nowadays infinite scrolling is as well, but more in the mobile space.
As with everyhing, it will always depend upon your specific target audience and their usage pattern, i.e. if mobile users, pagination is way worse technique.
To the discussions regard, the smashingmag article already came to a wonderful compromise, a conclusion that will fit even most people who can not apply a/b testing a sample size x - infinite scroll for the first hits and then add a "load more" (or whatever term) CTA which also comes in tow with a footer.
This will increase loading time, as only x are loaded first and will not aggregate mental effort with every infinite scroll load that let's you in the dark about how much you still can load. (which these aside nav information feedback modules are great for in the discussion thread, but are not available in the topic list, right?)
So, infinite scroll first items x -> load more CTA + footer == usability compromise.
